Prepare the Base

1. Melt the Cream Cheese: In a medium saucepan, combine the cream cheese and milk over low heat. Stir frequently until the cream cheese is completely melted and smooth.
2. Add Sour Cream: Stir in the sour cream, and continue to cook, stirring constantly to combine it with the melted cream cheese.
3. Add Spices: Sprinkle in the garlic powder, onion powder, salt, and pepper. Stir well to blend the seasonings into the mixture.

Add the Cheese and Chilies

4. Melt the Cheese: Gradually add in the shredded white cheddar and Monterey Jack cheese, stirring constantly to ensure the cheese melts evenly. This will create a smooth, cheesy base.
5. Stir in the Chilies and Jalapeños: Add the green chilies and jalapeños (if using), stirring until they are fully incorporated.

Simmer and Adjust Consistency

6. Simmer: Allow the dip to simmer on low heat for about 5-10 minutes, stirring occasionally. This helps the flavors meld together.
7. Adjust Consistency: If the dip seems too thick, add a little more milk to reach your desired consistency. Continue stirring until the dip is smooth and creamy.

Serve and Garnish

8. Serve Warm: Transfer the dip to a serving bowl, and top with fresh cilantro or green onions if desired for a burst of color and flavor.
9. Serve with Accompaniments: Serve the dip with tortilla chips, sliced veggies, crackers, or even drizzle over nachos.